An organic light-emitting device includes an anode, a cathode, and an organic compound layer disposed therebetween. Electrons and holes are injected from the electrodes into the organic compound layer to generate excitons of the light-emitting organic compound in the organic compound layer, and the organic light-emitting device emits light when the excitons return to the ground state.
The organic light-emitting device is also referred to as organic electroluminescent device or organic EL device. Organic light-emitting devices have remarkably progressed recently, and low driving voltages, high luminance, various emission wavelengths, rapid response, and reductions in size and weight of light-emitting devices are possible. However, in the organic light-emitting devices, the organic compound itself emits light, and thereby the lifetime is short, and there is a demand for further extension of the lifetime.
As a fluorescence-emitting material used in an organic light-emitting device, PTL 1 proposes a compound having a basic skeleton of dibenzo[a,c]tetracene shown as H1 below. NPL 1 reports on molecular orbital calculation of benzo[h]hexaphene shown as H2 below.

The compound disclosed in PTL 1 has a highly symmetrical basic skeleton and is thereby highly crystallizable. Consequently, a thin film formed of this compound tends to cause a change in film structure as a result of crystallization.
The compound disclosed in NPL 2 is an unsubstituted fused ring compound and is thereby highly crystallizable. In addition, the compound itself is readily oxidized and is thus unstable.
Furthermore, NPL 2 merely shows the organic compound represented by H2 as a model for molecular orbital calculation and is not referred to as a material for organic light-emitting devices.